A hot tub should be a place to relax, not a source of constant troubleshooting. Yet many hot tub owners run into the same issues repeatedly, from cloudy water and strange odours to heating problems and noisy pumps.
The good news? Most hot tub problems stem from water chemistry or routine maintenance, not major breakdowns. Understanding the common causes can help you spot issues early, prevent damage, and keep your spa running smoothly year round.
Below is a breakdown of the most common hot tub problems, why they occur, and how to avoid them.
Common Hot Tub Issues
Common Water Chemistry & Water Quality Issues
Water chemistry problems are the most frequent cause of hot tub issues. When water isn’t balanced properly, it affects everything: clarity, comfort, and even your equipment.
Cloudy or Dirty Water
Cloudy water is one of the earliest signs that something is off.
Common causes include:
- High or low pH levels
- Low sanitiser (chlorine or bromine)
- Dirty or clogged filters
- Buildup of oils, lotions, and organic debris
How to prevent it:
Test your water regularly, clean your filters, and maintain proper sanitiser levels. Cloudy water rarely appears overnight; it’s usually the result of small issues compounding over time.
Green Water or Algae Growth
Green water or visible algae is a clear indicator that the water chemistry is out of balance.
Typical causes:
- Low sanitiser levels
- Unbalanced pH
- Warm water combined with sunlight and poor circulation
How to fix it:
Algae usually requires a shock treatment to kill organic growth, followed by rebalancing your sanitiser and pH levels. Cleaning the filters is essential after treatment.
Foamy Water
Foam forming on the surface of your spa water is off putting and not ideal.
Common reasons:
- Soap residue from swimwear
- Body lotions, oils, and cosmetics
- Organic matter buildup
- Old or contaminated water
Prevention tips:
Rinse swimsuits thoroughly (avoid laundry detergent buildup), encourage showering before use, and shock the water regularly to break down contaminants.
Strong Chemical or Chlorine Smell
A strong chlorine smell doesn’t mean too much chlorine; it usually means not enough free sanitiser.
What’s happening:
Chloramines (used-up chlorine) build up in the water, causing odour and irritation.
Solution:
Shock the spa to break down chloramines and restore effective sanitiser levels.
Skin or Eye Irritation
If your spa leaves your skin itchy or your eyes irritated, chemistry is likely to blame.
Common causes:
- Incorrect pH levels
- Too much or too little sanitiser
How to avoid it:
Keep pH between 7.2 and 7.8, test weekly, and adjust chemicals gradually rather than all at once.
Common Mechanical & Electrical Issues
Mechanical problems can sound intimidating, but many are triggered by simple maintenance oversights.
Hot Tub Won’t Heat
Few things are more disappointing than a cold hot tub when there are spa heating issues.
Possible causes include:
- Dirty or clogged filter restricting water flow
- Faulty heating element
- Tripped circuit breaker or electrical fault
What to check first:
Always start with the filter. Restricted water flow is one of the most common reasons heating systems shut down as a safety precaution.
Noisy Pump or Motor
Unusual noises are often early warning signs.
Common causes:
- Low water levels
- Clogged filters
- Air trapped in the plumbing
- Worn or failing motor bearings
Tip:
Address strange noises early; ignoring them can lead to more costly repairs down the line.
Weak or Non-Functioning Jets
If the jets lack pressure or stop working entirely, it’s usually a circulation issue.
Typical reasons:
- Dirty filters
- Low water level
- Airlocks after refilling the tub
Fix:
Bleed air from the system if needed, clean the filters, and ensure the water level is above the jets and skimmer intake.
Leaking Water
Leaks can be subtle or obvious; either way, they should never be ignored.
Common leak points:
- Pump seals
- Pipe unions
- Cracked or damaged plumbing
Leaks are more common after winter due to freeze damage (that is if you’re in a cold climate), so seasonal inspections are important.
Tripping Circuit Breaker
If your breaker keeps tripping, it’s a safety signal.
Possible causes:
- Heater malfunction
- Failing pump
- Ground fault issue
Electrical problems should always be addressed promptly, and in many cases, by a qualified technician.
Control Panel Error Codes
Modern spa pool issues display error codes to alert you to problems.
Common examples:
- “FLO” or “FLC” — water flow issue (often filter-related)
- “OH” — overheating, usually caused by restricted circulation
Never ignore error codes; they’re designed to prevent serious damage.
How Storms and Flooding Can Affect Hot Tubs
Severe weather events like heavy rain, storms, and flooding can also cause unexpected hot tub problems. Excess rainwater can dilute water chemistry, throwing off pH and sanitiser levels almost overnight. Flooding poses a bigger risk, as contaminated water can enter the spa, damage pumps, heaters, and control systems, and introduce debris into plumbing and filters. Power surges or outages during storms may also trip breakers or affect electrical components. After any major weather event, it’s important to test and rebalance the water, inspect filters and equipment, and avoid using the spa until you’re sure everything is clean, safe, and functioning correctly.
Preventative Maintenance Tips to Avoid Hot Tub Problems
Most spa issues can be prevented with consistent, simple maintenance.
Keep Filters Clean
Clean filters regularly and replace them as recommended. Filters are critical for water flow, heating efficiency, and overall performance.
Balance Water Chemistry Weekly
Test and adjust:
- pH: 7.2–7.8
- Alkalinity
- Sanitizer levels
Small, frequent adjustments are better than large corrections.
Maintain Proper Water Levels
Ensure water stays above the jets and skimmer intake to prevent airlocks and pump damage.
Shock the Water Regularly
Using a non chlorine shock helps destroy organic contaminants, keeping water clear and fresh.
Use a Clean, Properly Fitting Cover
A good cover:
- Keeps debris out
- Reduces chemical loss
- Prevents heat escape
- Extends equipment life
Final Thoughts
Common hot tub problems are usually symptoms of neglected maintenance rather than serious defects. By monitoring water chemistry, cleaning filters regularly, and responding promptly to unusual sounds or error codes, you can avoid most common issues altogether.
A little routine care goes a long way, keeping your spa clean, safe, and ready whenever you need a soak.